The invention relates to a press fitting for a pipe and, in particular, to a press fitting for a plastic pipe or plastic-metal composite pipe.
Such press fittings are basically known. They have a fitting body, with a supporting sleeve projecting from this body. The end of a pipe to be connected is pushed onto the supporting sleeve, whereupon a pressing sleeve is pressed onto the pushed-on pipe end from the outside. This pressing sleeve is preassembled to simplify assembly on the fitting body and consequently runs essentially concentric to the supporting sleeve.
Examples for the previously described type of press fitting are found in DE-A-42 31 623, DE-A-196 03 228, and DE-C-100 10 573.
For the press fittings that are described in the previously mentioned publications, the pressing sleeve is held directly on the fitting body. For this purposed, the fitting bodies have collars on which one end of the pressing sleeve is pushed. Alternatively, the fitting bodies could have axially oriented grooves with circumferential walls that surround the pressing sleeves from the outside (DE-A-42 31 623). In particular, fitting bodies for the connection of pipes with relatively large diameters require a not insignificant use of materials for the direct mounting of the pressing sleeves on the fitting bodies, because the collars or circumferential walls on which the pressing sleeves are held can also be considerable in their extent.
It is further known to fix pressing sleeves of press fittings by means of retaining rings made from plastic on the fitting bodies. Such press fittings are described in DE-U-295 03 019, DE-C-43 04 680, DE-C-198 56 999, DE-A-101 34 727, DE-B-102 33 559, EP-A-0 728 979, and EP-A-0 942 219. In the case of these known press fittings, the material consumption for the retaining ring is also not insignificant in the case of press fittings with relatively large diameters.
From DE-C-101 37 078 it is known, in the case of a press fitting, to secure the pressing sleeve on the fitting body against detachment by the engaging of an inner bead on the retaining end of the pressing sleeve behind an outer bead on the fitting body.